Ni Q, MacLeod R S, Punske B B, Taccardi B
Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City 84112-5000, USA.
J Electrocardiol. 2000;33 Suppl:189-97. doi: 10.1054/jelc.2000.20309.
The long-term goal of electrocardiography is to relate electric potentials on the body surface with activities in the heart. Many previously reported studies have focused on direct links between heart and body surface potentials. The goals of this study were first to validate computational methods of determining volume potentials and currents with high-resolution experimental measurements and then to use interactive visualization of thoracic currents to understand features of the electrocardiographic fields from measured cardiac sources. We developed both simulation and experimental studies based on a realistic shaped torso phantom containing an isolated, perfused dog heart. Interventions included atrial pacing, single pacing and simultaneously pacing at multiple locations on the ventricles. Simulated torso volume potentials closely matched measured potentials in the torso-tank preparation (mean correlation coefficients of 0.95). Simulation further provided a means of estimating the current field in the torso from the computed torso volume potentials and the local geometric and conductive properties of the medium. Applying these techniques to the torso electric fields under a variety of pacing conditions, we have further demonstrated that thoracic current can provide many insights into the relationship between heart surface potential and body surface potentials. Specifically, we have shown that geometric factors including cardiac source configuration and location play an important role in determining to what extent electric activity in the heart is directly visible on the body surface electrocardiogram. The computation and visualization toolkit we developed in this study to explore current fields associated with cardiac events may provide new insights into electrocardiology.
心电图的长期目标是将体表的电位与心脏活动联系起来。许多先前报道的研究都集中在心脏与体表电位之间的直接联系上。本研究的目标首先是通过高分辨率实验测量来验证确定容积电位和电流的计算方法，然后利用胸部电流的交互式可视化来从测量的心脏源理解心电图场的特征。我们基于一个包含孤立的、灌注的犬心脏的逼真形状的躯干模型开展了模拟和实验研究。干预措施包括心房起搏、单部位起搏以及在心室多个部位同时起搏。模拟的躯干容积电位与躯干水箱准备中的测量电位紧密匹配（平均相关系数为0.95）。模拟进一步提供了一种从计算出的躯干容积电位以及介质的局部几何和传导特性来估计躯干中电流场的方法。将这些技术应用于各种起搏条件下的躯干电场，我们进一步证明胸部电流可以为心脏表面电位与体表电位之间的关系提供许多见解。具体而言，我们已经表明，包括心脏源配置和位置在内的几何因素在确定心脏电活动在体表心电图上直接可见的程度方面起着重要作用。我们在本研究中开发的用于探索与心脏事件相关的电流场的计算和可视化工具包可能会为心电学提供新的见解。
